Improvement in door-locks



I. P. TURNER.

DOOR-LOCK. No.185,594. P aaaa ted Dec.19,1876.

" ilil UNITED STATES PATENT OFFICE.

ISAAC P. TURNER, OF TROY, NEW YORK.

IMPROVEMENT lN DOQR-LOCKS.

Specification forming part of Letters Patent No. 185,594, dated December 19, 1876; application filed March 25, 1876.

greater security against breaking or picking the same, than in locks as heretofore constructed, and to produce a lock that can only -be unlocked by the aid of a secondary key,

which will be caught, and held while the lock is in an unlocked condition, and only liberated on the locking of the same, thus serving to indicate to the holder, when in his posses sion, that the lock is securely fastened.

The invention consists in the combination with the bolt of the lock, of a rod adapted to work through the aperture in the end of a secondary key, for holding the same in the look, as will be hereinafter described.

The invention also consists in the combination, with the bolt of the lock, of a tumbler and a rod, arranged to operate in connection with a secondary key, as will more fully hereinalter appear.

In the drawing, Figure 1 represents a perspective view of a portion of a door with my improved lock applied to the same. Fig. 2 represents a sectional view through the door and lock. Fig. 3 represents an interior view of the upper portion of my lock; Fig. 4, a detached interior view, showingthe tumbler engaging the bolt, and Fig. 5 a view of the secondary key.

The letter A represents a door of ordinary construction, and B the lock-casing. 0 represents the bolt of the lock, which may be of any approved construction, and operated as usual, by means of an ordinary key. D represents a tumbler pivoted in the upper part of the lock-casing, the lower end of which rests upon the top of the bolt, falling by its own weight into a recess, E, in the bolt, when the same is in position for locking, and serving to hold it in said position until raised or elevated by means of the secondary key F. Said key is shown detached in Fig. 5, and consists essentially of a flat bar of metal provided with an aperture at its end, for the purpose to be hereinafter explained.

In the present instance, said key is pivoted between two similar bars for the purpose of folding, in order that it may be conveniently carried.

The letter G represents a short bar of metal secured to the upper edge of the bolt, and parallel with its line of motion, in such position as to Work into and through the aperture in the secondary key, so as to hold said key when the bolt is unlocked, and clear said aperture and free the key when the bolt is locked.

The operation of my invention will be readilyunderstood from the foregoing description. The bolt is moved by the key in the ordinary manner in locking and unlocking. When locked, however, the bolt is held by the tumbler D, and cannot be withdrawn until said tumbler is lifted by means of the secondary key. Upon withdrawing the bolt the bar Gr enters the aperture in the end of the secondary key, and prevents its removal until the lock is again locked.

What I claim, and desire to secure by Letters Patent, is

1. In combination, with the bolt of the lock, the rod G, adapted to Work through the aperture in the end of the secondary key, and hold the same in the lock, substantially asdescribed.

2. In combination, with the bolt of thelock, the tumbler D, and rod G, arranged to operate in connection with a secondary key, substantially as described.

In testimony thatIclaim theforegoing I have hereunto set my hand in the presence of the subscribing witnesses.

. ISAAC P. TURNER.

Witnesses:

Jos. L. OooMBs, A. H. NORRIS. 

